G-CLASS: geosynchronous radar for water cycle science – orbit selection and system design

Stephen E. Hobbs; Andrea Monti Guarnieri; Antoni Broquetas; Jean-Christophe Calvet; Nicola Casagli; Marco Chini; Rossella Ferretti; Thomas Nagler; Nazzareno Pierdicca; Christel Prudhomme; Geoff Wadge

doi:10.1049/joe.2019.0601

G-CLASS: geosynchronous radar for water cycle science – orbit selection and system design

The Journal of Engineering ◽

10.1049/joe.2019.0601 ◽

2019 ◽

Vol 2019 (21) ◽

pp. 7534-7537 ◽

Cited By ~ 2

Author(s):

Stephen E. Hobbs ◽

Andrea Monti Guarnieri ◽

Antoni Broquetas ◽

Jean-Christophe Calvet ◽

Nicola Casagli ◽

...

Keyword(s):

System Design ◽

Water Cycle ◽

Orbit Selection

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Next Generation Gravity Mission Elements of the Mass Change and Geoscience International Constellation: From Orbit Selection to Instrument and Mission Design

Remote Sensing ◽

10.3390/rs13193935 ◽

2021 ◽

Vol 13 (19) ◽

pp. 3935

Author(s):

Luca Massotti ◽

Christian Siemes ◽

Günther March ◽

Roger Haagmans ◽

Pierluigi Silvestrin

Keyword(s):

Water Cycle ◽

Temporal Variations ◽

Mass Change ◽

Mission Design ◽

Next Generation ◽

Gravity Signal ◽

Climate Series ◽

Gravity Mission ◽

Orbit Selection

ESA’s Next Generation Gravity Mission (NGGM) is a candidate Mission of Opportunity for ESA–NASA cooperation in the frame of the Mass Change and Geosciences International Constellation (MAGIC). The mission aims at enabling long-term monitoring of the temporal variations of Earth’s gravity field at relatively high temporal (down to 3 days) and increased spatial resolutions (up to 100 km) at longer time intervals. This implies also that time series of GRACE and GRACE-FO can be extended towards a climate series. Such variations carry information about mass change induced by the water cycle and the related mass exchange among atmosphere, oceans, cryosphere, land and solid Earth and will complete our picture of global and climate change. The main observable is the variation of the distance between two satellites measured by a ranging instrument. This is complemented by accelerometers that measure the nongravitational accelerations, which need to be reduced from ranging measurements to obtain the gravity signal. The preferred satellite constellation comprises one satellite pair in a near-polar and another in an inclined circular orbit. The paper focuses on the orbit selection methods for optimizing the spatial sampling for multiple temporal resolutions and then on the methodology for deriving the engineering requirements for the space segment, together with a discussion on the main mission parameters.

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